bims-covind Biomed News
on COVID-19 and Immunology: nutrition and diet
Issue of 2020–12–06
thirteen papers selected by
Aimee Cook, Newcastle University



  1. Int J Endocrinol Metab. 2020 Jul;18(3): e107669
      
    Keywords:  Biomarkers; COVID-19; Coronavirus Disease 2019; Vitamin D; Vitamin D Deficiency
    DOI:  https://doi.org/10.5812/ijem.107669
  2. Nutrients. 2020 Nov 27. pii: E3642. [Epub ahead of print]12(12):
      Evidence from observational studies is accumulating, suggesting that the majority of deaths due to SARS-CoV-2 infections are statistically attributable to vitamin D insufficiency and could potentially be prevented by vitamin D supplementation [...].
    DOI:  https://doi.org/10.3390/nu12123642
  3. Med Hypotheses. 2020 Nov;pii: S0306-9877(20)32424-5. [Epub ahead of print]144 110176
      COVID-19 infection causes considerable morbidity and mortality, especially to those who are aged, have impaired renal function and are obese. We propose to examine the potential utility of oral activated charcoal with the hypothesis that such treatment would lower absorption of microbiome derived toxins and ameliorate systemic oxidant stress and inflammation.
    DOI:  https://doi.org/10.1016/j.mehy.2020.110176
  4. Infect Chemother. 2020 Nov 13.
      Vitamin C, also known as L-ascorbic acid, is an essential vitamin with pleiotropic functions, ranging from antioxidant to anti-microbial functions. Evidence suggests that vitamin C acts against inflammation, oxidative stress, autophagy chaos, and immune dysfunction. The ability to activate and enhance the immune system makes this versatile vitamin a prospective therapeutic agent amid the current situation of coronavirus disease (COVID-19). Being highly effective against the influenza virus, causing the common cold, vitamin C may also function against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and its associated complications. Severe infections need higher doses of the vitamin to compensate for the augmented inflammatory response and metabolic demand that commonly occur during COVID-19. Compelling evidence also suggests that a high dose of vitamin C (1.5 g/kg body weight) in inflammatory conditions can result in effective clinical outcomes and thus can be employed to combat COVID-19. However, further studies are crucial to delineate the mechanism underlying the action of vitamin C against COVID-19. The current review aims to reposition vitamin C as an alternative approach for alleviating COVID-19-associated complications.
    Keywords:  COVID-19; Immune response; Inflammation; SARS-CoV-2; Vitamin C
  5. Med Hypotheses. 2020 Nov;pii: S0306-9877(20)32656-6. [Epub ahead of print]144 110272
      Obese individuals seem to be at the highest risk of contracting COVID-19 infection. Furthermore, severity of morbidity and mortality rates are higher in the developed world as compared to the developing world. One probable reason for this difference could be the difference in living conditions and exposure to other infections. Secondly, the difference in food especially, alcohol use may have deteriorating effects superimposed with obesity. Our hypothesis suggests that a combination of alcohol consumption and obesity causes low immunity and makes the individual prone to develop 'cytokine storm' and 'acute respiratory distress syndrome'; the hallmark of COVID-19 mortality and morbidity. Thus, we propose that reducing any one trigger can have a beneficial effect in combating the disease severity.
    DOI:  https://doi.org/10.1016/j.mehy.2020.110272
  6. Med Hypotheses. 2020 Nov;pii: S0306-9877(20)32471-3. [Epub ahead of print]144 110218
      Covid-19, caused by SARS-CoV-2, has major world-wide health-related and socio-economic consequences. There are large disparities in the burden of Covid-19 with an apparent lower risk of poor outcomes in East Asians compared to populations in the West. A recent study suggested that Covid-19 leads to a severe extrahepatic vitamin K insufficiency, which could lead to impaired activation of extrahepatic proteins like endothelial anticoagulant protein S in the presence of normal hepatic procoagulant activity. This would be compatible with the enhanced thrombogenicity in severe Covid-19. The same study showed that vitamin K antagonists (VKA) that inhibit vitamin K recycling, had a greater impact on procoagulant activity than on the activation of extrahepatic vitamin K-dependent proteins during SARS-CoV-2 infections. A genetic polymorphism in the vitamin K epoxide reductase complex 1, VKORC1 -1639A, is particularly prevalent in East Asia and associates with low vitamin K recycling rates. Carriage of the allele may be regarded as bioequivalent to low-dose VKA use. We speculate that VKORC1 -1639A confers protection against thrombotic complications of Covid-19 and that differences in its allele frequency are partially responsible for the differences in Covid-19 severity between East and West.
    DOI:  https://doi.org/10.1016/j.mehy.2020.110218
  7. Med Hypotheses. 2020 Nov 12. pii: S0306-9877(20)33265-5. [Epub ahead of print] 110374
      COVID-19 exacts a disproportionate toll on both the elderly and those with diabetes; these patients are more likely to require costly intensive care, longer hospitalisation, and die from complications. Nations would thus find it extremely difficult to either lift or sustain socially, economically, and politically damaging restrictions that keep this group of people safe. Without a vaccine, there is thus an urgent need to identify potential modifiable risk factors which can help manage overall fatality or recovery rates. Case fatality rates are highly variable between (and even within) nations; nutritional differences have been proposed to account significantly for this disparity. Indeed, vitamin B12 deficiency is a common denominator between the elderly and those with diabetes. The question on hand thus lies on whether managing B12 deficiencies will impact COVID-19 fatality outcome or recovery rates. Herein, we review the latest evidence that shows that B12 deficiency associates in multiple areas very similar to where COVID-19 exerts its damaging effects: immunologically; microbiologically; haematologically; and through endothelial cell signalling-supporting the hypothesis that B12 deficiency is a potential modifiable risk factor in our fight against COVID-19.
    Keywords:  COVID-19; Diabetes mellitus; Elderly; Folate; Homocysteine; Immune system; One-carbon metabolism; Sars-Cov-2; Vitamin B12
    DOI:  https://doi.org/10.1016/j.mehy.2020.110374
  8. Brief Bioinform. 2020 Dec 01. pii: bbaa330. [Epub ahead of print]
      The outbreak and pandemic of SARS-CoV-2 in 2019 has caused a severe public health burden and will challenge global health for the future. The discovery and mechanistic investigation of drugs against Coronavirus disease 2019 (COVID-19) is in deadly demand. The paper published by Li and colleagues proposed the hypothesis that vitamin C combined with glycyrrhizic acid in treating COVID-19 and its mechanistic investigation was performed by a database-based network pharmacology. In this letter, we present critical comments on the limitations and insufficiencies involved, from both the perspective of network pharmacology and current evidence on COVID-19.
    Keywords:  COVID-19; glycyrrhizic acid; network pharmacology; vitamin C
    DOI:  https://doi.org/10.1093/bib/bbaa330
  9. Diseases. 2020 Nov 26. pii: E44. [Epub ahead of print]8(4):
      The therapeutic potential of melatonin as a chronobiotic cytoprotective agent to counteract the consequences of COVID-19 infections has been advocated. Because of its wide-ranging effects as an antioxidant, anti-inflammatory, and immunomodulatory compound, melatonin could be unique in impairing the consequences of SARS-CoV-2 infection. Moreover, indirect evidence points out to a possible antiviral action of melatonin by interfering with SARS-CoV-2/angiotensin-converting enzyme 2 association. Melatonin is also an effective chronobiotic agent to reverse the circadian disruption of social isolation and to control delirium in severely affected patients. As a cytoprotector, melatonin serves to combat several comorbidities such as diabetes, metabolic syndrome, and ischemic and non-ischemic cardiovascular diseases, which aggravate COVID-19 disease. In view of evidence on the occurrence of neurological sequels in COVID-19-infected patients, another putative application of melatonin emerges based on its neuroprotective properties. Since melatonin is an effective means to control cognitive decay in minimal cognitive impairment, its therapeutic significance for the neurological sequels of SARS-CoV-2 infection should be considered. Finally, yet importantly, exogenous melatonin can be an adjuvant capable of augmenting the efficacy of anti-SARS-CoV-2 vaccines. We discuss in this review the experimental evidence suggesting that melatonin is a potential "silver bullet" in the COVID 19 pandemic.
    Keywords:  COVID-19 pandemic; aging; anti-SARS-CoV-2 vaccination; chronotherapy; cognitive impairment; cytoprotection; diabetes; inflammation; melatonin; metabolic syndrome; neurodegeneration; oxidative stress; renin–angiotensin system
    DOI:  https://doi.org/10.3390/diseases8040044
  10. Respir Med. 2020 Nov 19. pii: S0954-6111(20)30373-5. [Epub ahead of print]176 106233
       INTRODUCTION: The Coronavirus disease (COVID-19) infection is caused by the novel Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) primarily affecting the lungs. All tobacco-related illnesses including asthma, chronic obstructive pulmonary disease (COPD), and coronary artery disease are known to reduce the lung capacity and impair the immune system of the body and can greatly influence the ability to fight the novel coronavirus. The purpose of this state-of-the-art literature review is to summarize the evidence of the association of tobacco use with the severity of the COVID-19 manifestations.
    METHOD: Articles describing the association of tobacco use with the severity of COVID-19 manifestations were searched on PubMed, MEDLINE, and Google. This review covers the relevant studies on the subject published from January 1, 2020 to September 10, 2020.
    RESULTS: Tobacco use in all forms, whether smoking or chewing, is significantly associated with severe COVID-19 outcomes. Pre-existing comorbidities in tobacco users such as cardiovascular diseases, diabetes, respiratory diseases and hypertension were found to further aggravate the disease manifestations making the treatment of such COVID-19 patients more challenging due to their rapid clinical deterioration.
    CONCLUSIONS: Current review indicates that nicotine exposure is linked to cardiopulmonary vulnerability to COVID-19 and tobacco use can be a potential risk factor for not only getting the viral infection but also its severe manifestations. The current pandemic provides a teachable moment to break the cycle of nicotine addiction and accelerate national tobacco control programs to achieve a tobacco-free world.
    Keywords:  ACE-2; COVID-19; Cessation; Severity; Tobacco use
    DOI:  https://doi.org/10.1016/j.rmed.2020.106233
  11. Med Hypotheses. 2020 Nov;pii: S0306-9877(20)32191-5. [Epub ahead of print]144 110287
      COVID-19 affects males twice as frequently as females with significantly increased severity and mortality. Current data suggest a direct correlation between the lower level of serum testosterone, inflammatory cytokines, disease severity, and poor clinical outcomes among male patients with COVID-19. The gradual decline in total and free testosterone levels has a direct correlation with serious pulmonary complications requiring advanced care (ICU, ventilators, ECMO, etc.). SARS-CoV-2 utilizes Angiotensin-Converting Enzyme II (ACE2) for entry in the host cell, and Transmembrane Protease, Serine 2 (TMPRSS2) to prime spike protein of SARS-CoV-2. Testosterone induces ACE-2 expression, a critical pulmonary protective enzyme. Low testosterone levels in males have a direct correlation with the high probability of ICU admission and the worse disease outcome (ARDS, duration of ICU stay, mortality). On the contrary, however, high testosterone levels can lead to thrombosis which is also one of the fatal manifestations in COVID-19 patients. A critical evaluation of the serum testosterone and its relevance to COVID-19 is warranted to re-evaluate strategies to effectively triage, prioritize, and manage high-risk patients for ICU admission, survival outcomes, targeted solutions, and operational algorithms.
    Keywords:  ACE2; COVID-19 outcomes; SARS-CoV-2; Sex; TMPRSS2; Testosterone
    DOI:  https://doi.org/10.1016/j.mehy.2020.110287